ZyXEL Communications NSA-220 User Manual

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Chapter 6 Storage Screens
NSA-220 User’s Guide
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• OK means the USB connected device is functioning properly. 
• Resync when you create a RAID volume.
• Recovering appears when repairing a RAID 1 volume. (A RAID1 volume was once 
degraded, but you have installed a new disk and the NSA is restoring the RAID1 volume  
to a healthy state.)
• Degraded when a volume is currently down, but can be fixed. Data access may be slower 
from a degraded volume, so it’s recommended that you replace the faulty disk and repair 
the volume as soon as you can.
• Inactive when a disk is missing from a RAID 0 volume or a two-disk JBOD volume. The 
volume is unusable. If you removed one of the disks you should be able to re-install it and 
use the volume again (as long as you did not change anything on the disk). If a disk has 
failed, you need to replace it and re-create the whole volume. All data will be lost. See 
page 
 for how to install or replace a hard drive. 
• Down when a volume is down and can not be fixed.
A down RAID volume cannot be used until you repair or replace the faulty disk(s) in the 
volume. Degraded means one of the disks in the RAID volume is not available but the volume 
can still be used. For a degraded volume, you should replace the faulty disk as soon as possible 
to obtain previous performance. See your Quick Start Guide for more information on replacing 
a disk. 
If it’s down, then the only indication is that you can no longer transfer files to/from the shares 
in the down volume. If it’s degraded, then file transfer to/from the shares in the degraded 
volume will be slower. 
"
There is no explicit message from CIFS that tells users their volume is 
degraded or down. 
6.6  Disk Replacement Restrictions
See the Quick Start Guide for information on replacing disks in the NSA. When replacing a 
disk in a degraded or down RAID volume, the new disk must be at least the same size or 
bigger than the other disks that are already in the RAID volume, so as all data in the volume 
can be restored.
For example, if you have RAID with 250 GB disks, you must put in a 250 GB or bigger disk as 
a replacement in order to restore all original data in that volume. If you put a bigger disk, the 
extra space on the disk will not be used.
"
The NSA repairs a RAID volume automatically when you replace a faulty disk 
with a disk that does not contain a volume.